Fabrication of crack-free photonic crystal films: Via coordination of microsphere terminated dendrimers and their performance in invisible patterned photonic displays

We report herein the fabrication of large-area, crack-free and flexible colloidal photonic crystal (CPC) films composed of composite microspheres. These microspheres were prepared by coating Ag nanoparticles (NPs) on carbosilane-thioether generation 3 vinyl-terminated (G3-Vi) dendrimer functionalized polystyrene (PS-co-G3Vi) microspheres by in situ generation. The coordination interaction among the microspheres imposes positive effects on the assembly of colloidal particles, allowing the construction of large-area crack-free quality functional colloidal photonic crystal (CPC) films. Benefited from the surface charge of these microspheres, invisible patterned photonic display devices were further obtained to show good stability, reproducibility and angle-independent characteristics, which are promising for optical devices, such as photoelectric control systems and anti-counterfeit technology.